High tension transformer



2 1933- F. J. FISCHER ET AL. ,8 8

HIGH TENS ION TRANSFORMER Filed June 4, 1930 I Patented F eb. 21, 1933 UNITED STATES PATENT OFFICE FRANZ JOSEPH FISCHER AND KURT AUGUST ETERZEL, OI DBESDEN, GERMANY, A8-

SIGNORS TO KOCH & STEBZEL AKTIENGESELLSCHAIT, OF DRESDEN, GERMANY, A

COMPANY OF GERMANY men TENSION TRANSFORMER Application filed June 4, 1980, Serial No. 459,280, and in Germany June 5, 1929.

10 mencement of the inmost winding layer is carried through the flange of the spool.

The invention is based on the idea of so winding the ends of the separate layers closely against the inner side of the flange of the spool, that each surface element of the inner side of the flange has im arted thereto the potential of the last winding of the adjacent layers. It is also thereby made possible to reduce the flange of the spool outwards corresponding to the reduced potential with respect to the standard potential. In order that the first or the last winding of each layer rests closely against the inner side of the flange, the inclination is so chosen that the windings of the layer at any time following, rest in the spaces of the windings of the underneath layer.

A further object consists in the arrangement of a thin sheet of metal so wrapped around the core of a coil spool as to form a helical slit in order to insure an even distribution of potential over the core.

The center part of the spool, that is, the surface of the spool surrounded by the innermost winding layer, may be provided with a metallized surface which is connected with the high potential end of the winding, that is, with the beginning of the innermost high potential winding layer.

This metallizing of the center art is particularly advantageous in trans ormers wound in the special manner described in the aforesaid specification on account of the fact that the maximum potential stress to which any part of the spool is subjected is carried by the said center part of the spool. The metallizing of the center part has the effect of distributing the potential stress uniformly over the whole surface of the center part of the spool.

According to the present invention there is provided a high potential transformer of the type described in the aforesaid specification, in which the innermost layer of the high potential winding is formed by a slit conductive plate placed round the center part of the spool. This construction of the innermost high potential winding layer has, in addition to the advantage of a ple construction, the further advantage that the initial wire coils need not be made of thicker cross section.

In order that the invention may be clearly understood and readily carried into effect the same will now be described with reference to the accompanying drawing in which z- Fig. 1 is a perspective view of the coil spool of the transformer and the conductive plate before the latter is wound on the spool.

Fig. 2 is a view similar to Fig. 1 showing the clonductive plate wrapped around the coil spoo Fig. 3 is an enlarged view of the coil spool with parts in section.

Fig. 4 is a sectional view taken substantially along the line AA of Fig. 3 and looking in an upward direction.

Referring to the drawing, a metal plate 124 having, in the unrolled condition, a substantially rhomboidal shape, is provided at one of its acute-angled corners with a projection 118 which is inserted into a slot 119 in the base of the flange 16 of the coil spool. The parallelogram shaped plate 124 is then wrapped round the center part 15 of the coil spool. The dimensions of the plate are such that the ends of the loop formed do not quite meet so that a helical slit 10 is formed as clearly shown in Figure 2. At the acute-angled corner of the plate 124, remote from the projection 118 is connected one end of the commencement 120 of the high potential winding which is subsequently wound in layers over the plate 124, (Fig. 3).

It will be observed that the layers of the high potential winding 120 have their ends wound close to the inner side of the adjacent flange 16. By ensuring that the end turns of each layer are close up against the wall of the flange no air gaps are left which might more simpermit discharge to take place. Thus a creeping discharge along-the inner side of the flange is prevented.

The lower portion of the spool 15 as shown in Fig; 3 is twisted relative to the upper portion to indicate the manner in which the high potential winding 120 is connected tothe metal sheet 124 and wound upon the spool.- The outer end of the coil winding 120 is, of course,.conn ected to the ground. v

The lead-outinsulator 17 preferably forms one piece with the single part spool 11, while the projection 118 of the plate 124 is permanently secured in the hollowspace 121 of the insulator 17 by means of metal 122such as lead, which is introduced in a molten condition. On the upper surface. of the cast metal What we claim and desire to secure by Let'- ters Patent of the United States is 1. A high potential measuring transformer of the class described, having a single piece flanged spool of insulating material, said spool provided with a high potential winding,

formed in layers whereby its potential increases from the outer lying initial potential towards the core surrounded thereby, the ends of the layers being wound close to the inner side of th'e'flanges of the spool, so that each surface elementvof the inside of the flange has imparted thereto the potential of the last winding of the adj acent layer, the innermost high potential winding layer being formed by a slit conductive plate placed around the centerpart of the spool.

2. A high potential measuring transformer of the class described, having a single piece flanged spool of insulating material, said spool provided with a high potential winding formed in layers whereby its potential increases from the outer lying initial potential towards the core surrounded thereby, the ends of the layers being wound close to the inner side of the flange of the spool, so that each surface element of the inside of the flange has imparted thereto the potential of the last winding of the adjacent layer, the innermost high potential winding layer being formed by a slit conductive plate placed around the center part of the spool, said plate before being wound on the spool being in the shape of aparallelogram.

3. A high potential measuring transformer of the class described, having a single piece flanged spool of insulating material, said winding ofothe adjacent layer, theinnermost high potential winding layer being formed bya slit conductive plate placed around the centerpart of the spool, said plate before being fitted on the spool having a shape of a parallelogram, said flange having an opening therein, a projection in the inner end of the I plate extending through said opening, a connecting insulator mounted on said flange above said opening and through which said projection extends and metallic means for securing the projection to the insulator.

a. A high potential measuring transformer of the class described, having a single piece flanged spool of insulating material, said spool provided with a high potential winding formed in layers whereby its otential iny itspotential in-.

e flange of the spool, so that each creases from the outer lying initlal potential towards the core surrounded thereby, the ends of the layers being wound close to the inner side of the flange of the spool, so that each surface element of. the inside of the flange has imparted thereto, the potential of the last winding of the adjacent layer, the innermost high potential winding layer being formed by a slit conductive plate placed around the center of the spool, said plate before being fitted on the spool having a shape ofa parallelogram, said flange having an opening therein, an insulator mounted on the flange above said opening, said plate having a projection arranged to extend through said opening into the insulator, a material casting-in means for connecting the projection to the insulator, and a connecting spring resting on the upper surface of the material casting-1n means.

g 5. A high potential measuring transformer of the class described, including a spool of insulating material, an insulator mounted on said spool, a metallic conductive plate of substantially rhomboidal shape wound on said spool and having a projection extending into said insulator, and a high potential winding connected to an opposed portion of the plate and wound in layers over said spool.

6. A high potential measuring transformer of the class described, including a flanged spool of insulating material, an insulator connected'to said spool, a'thin sheet of substantially rhomboidal shaped metal wound around the core of the spool, said sheet hav ing a projection extending into said insulator and connected thereto by a fusible metal, and a high potential winding connected to said plate and wrapped around the spool.

7. A high potential measuring transformer naoam of the class described, including a ti spool of insulatin material, a high tential winding wrappe on said spool, said winding having its inner layer formed by a slit conductive plate wrapped around the core of the spool, an insulator connected to the spool, said plate having a projection extending into said insulator, a safety fuse mounted in said insulator, metallic means connecting the projected portion of the plate to the insulator, and a spring interposed between said projection and the adjacent end of the safety use.

8. A high potential measuring transformer of the class described having a flanged spool of insulating material, an insulator integrally connected to the spool, a thin sheet of substantially rhomboidal shaped metal wound around the core of the spool, said sheet having a projection extending into said insulator, metallic means for connecting the proj ection to the insulator, a safety fuse in said insulator, a spring connecting said projection with said safety fuse, a high potential winding extending from an opposed portion ofsaid plate and wrapped around said-core, whereby to insure an even distribution of potential over the core of the spool.

9. A high potential measuring transformer, including a s 001 having an insulator thereon, a sheet 0 metallic material of substantially parallelogram shape wrapped around the spool to form a helical slit, said sheet having a projection on its inner end' extending to said insulator, fusible means connecting the projection to saidinsulator, and a high potential winding wrapped on said spool and connected to said sheet.

10. A high potential transformer including a spool, a sheet of metallic material of substantially rhomboidal shape wrapped around said spool, anda high potential winding connected to said'sheet and wrapped on the spool, whereby to insure an even distribution of potential over the spool.

FRANZ JOSEPH FISCHER. KURT AUGUST STERZEL. 

